Pizza Hut workers are accusing a franchise of blatantly unlawful behaviour alleging it has altered timesheets, docked wages and stopped payments per delivery.
Glenshire Group which runs all 22 Pizza Hut delivery outlets in Scotland has been served with a grievance by the Unite union on behalf of drivers who claim they were told of changes by text with no consultation.
Delivery driver, Cian, told the BBC that Glenshire had shown a complete disdain for their staff and their customers and said it was quite honestly abysmal.
Glenshire said it is "absolutely committed to robust employment practices" and said it is "listening to our colleagues, to understand where there are concerns".
Cian, 30, has been delivering pizzas in the west of Glasgow for more than two years. An employee of Pizza Hut franchise, Glenshire Group, he has always been paid the National Living Wage plus a fee of £1.45 per delivery.
But he said his terms and conditions were changed without consultation or warning.
He said two weeks ago he and several other drivers were told via text message that his pay had increased to £12.21 an hour but he had lost his £1.45 delivery payments, or what the company calls "discretionary driver commissions".
The £1.45 would pay for my fuel and a tiny bit of the running cost of my car but Ive been living paycheque to paycheque," he told the BBC.
"We had multiple drivers just quit because they simply cant afford to do this job if theyre having to pay for their own fuel. Theres one shop that has lost every single one of their drivers.
In a letter to staff dated 10 March, seen by the BBC, Glenshire said: "We have removed discretionary driver commissions with effect from today. This change is necessary to ensure the sustainability of our operations."
The letter does not state that the company has any plans in place to ensure drivers expenses will be paid by Glenshire.
In a statement to the BBC, the company said that driver commissions have not been reduced, rather the remuneration model has changed from a per delivery amount to a per mile basis".
Unites head of hospitality, Bryan Simpson has accused Glenshire of a cynical attempt to offload over 100 drivers before the rise in employers National Insurance Contributions (NICs), the National Minimum Wage (NMW) and the National Living Wage on 1 April.
Among the increases next month, the National Living Wage for people aged 21 and over will rise from £11.44 to £12.21.
"I have never seen something so blatantly unlawful occur, even in an industry, frankly, that is not known for decent workers rights. This is the worst that Ive came across in over a decade," Mr Simpson said.
He said the loss of drivers commission per delivery could effectively mean that "these workers are going to be brought below the minimum wage.
"Theyre going to be losing thousands of pounds a year. So, as far as we are concerned, this is fire and rehire under a different name.
Unites grievance, seen exclusively by the BBC, also accused Glenshire of acting fraudulently by going into old staff timesheets and retroactively adding unpaid 20 minute rest breaks.
In a text message seen by the BBC, Glenshire director Zibby Ghafoor told store managers all time sheets have been deleted for last week..can we please add breaks in."
Unite claims Glenshire unlawfully deducted these breaks from their wages.
In its statement, Glenshire said that there have been "no changes to break policies".
A manager called Adam, not his real name, said he works for hours on his own in his store. He said its simply not possible to take breaks.
"You do not get your 20 minutes of uninterrupted time ever...so not only do we not get breaks, we now get charged for the breaks that we dont take.
Cian says its his civic duty to speak out even though he knows it could put him at risk of losing his job. Im trying to help people who cant stand up for themselves, because the way the Glenshire group have treated everyone is abysmal. The long term ramifications of what they are doing, its just not worth me keeping my job.
Glenshire Group employs more than 200 staff including more than 100 delivery drivers although over the last few days, the BBC understands several have quit.
In the 10 March letter to staff, Glenshire said that with the increases in employer NICs and the National Living Wage rise on 1 April it was having to "reassess our driver delivery model in order to retain business viability".
It also said drivers could choose to switch from being employed to self-employed.
The letter stressed this would be a voluntary choice and would not be compulsory. Glenshire last night told the BBC there were "no blanket changes to self-employed contracts taking place".
Employment lawyer Joanne Moseley of Irwin Mitchell warned that from 1 April, when the new National Living Wage is introduced, Glenshire could be in breach of minimum wage regulations.
"If Glenshire doesnt reimburse its drivers for payments theyve incurred in connection with their employment - in this case their petrol expenses - they will be in breach of the NMW regulations. HMRC will investigate and has the power to impose financial penalties," she says.
Adam called on bosses of the Pizza Hut company to investigate the Glenshire franchise.
"Please be aware of what this company are doing to your brand. Please be aware of what theyre doing to the staff and all for their own benefit, all to save them money," he said.
A spokesperson for Pizza Hut UK said: "Pizza Hut is deeply committed to ensuring a safe and fair working environment for all employees and as such has strict policies in place that its franchise businesses must adhere to.
"Although Glenshire Group operates as an independent franchisee and is ultimately responsible for its own employment practices, we take these allegations seriously.
"Glenshire will be actively engaging in the coming days with any concerned employees, and we will continue to investigate this situation."